1. Field of the Invention
The present invention relates to an information processing apparatus, a lifetime monitoring method, and a program, and more particularly to an information processing apparatus, a lifetime monitoring method, and a program for monitoring the lifetime of a storage device including a flash memory.
2. Description of the Related Art
Hard disk drives have heretofore been in widespread usage as storage devices for use with information processing apparatus.
At present, however, the reliability of hard disk drives is not high enough. Therefore, systems which demand high operational reliability find it necessary to periodically replace the hard disk drive used therein or to have a backup storage device connected to the information processing apparatus in order to make up for the reliability shortage of the hard disk drive.
In recent years, semiconductor flash memories have been substantially improved in storage capacity and cost. Storage devices employing semiconductor flash memories are more reliable than hard disk drives. At present, therefore, storage devices employing semiconductor flash memories are used as storage devices for use with information processing apparatus.
The flash memory is, however, problematic in that storage elements thereof deteriorate when they repeatedly erase and rewrite information.
JP-A No. 2000-57000 discloses a microcomputer incorporating a flash memory. The disclosed microcomputer has a function that monitors the flash memory.
Specifically, the microcomputer has a nonvolatile memory, which is different from the flash memory, for storing a guaranteed rewrite count for the flash memory and an actual rewrite count for the flash memory. When the actual rewrite count exceeds the guaranteed rewrite count, an alarm signal is output.
JP-A No. H09-305497 discloses a recording and reproducing apparatus for monitoring each sector of a flash memory.
Specifically, a guaranteed erasure count and an accumulated erasure count for each sector are stored in the flash memory. When the accumulated erasure count exceeds the guaranteed erasure count, the information, which indicates that the accumulated erasure count exceeds the guaranteed erasure count, is reported to a microcomputer.
According to the microcomputer disclosed in JP-A No. 2000-57000 and the recording and reproducing apparatus disclosed in JP-A No. H09-305497, a storage area for storing the rewrite count is preset, and the rewrite count is stored in the preset storage area.
If such a storage area is not preset, then the rewrite count cannot be stored, and hence the flash memory cannot be monitored for deterioration.